The lasers are made from stacking light waves that add together into a larger wave in a process known as

The lasers are made from stacking light waves that add together into a larger wave in a process known as constructive interference. This happens only when waves would meet while they are traveling in the same medium. Constructive interference happens at any part of the medium where two waves moves in the same direction. When these waves would meet, they add up and make a larger wave. It is the interference of at leat two waves which produces a single amplitude where it is equal to the sum of the amplitudes of each wave that interfered. The other type is the destructive intereference where the result is a smaller wave.